package com.hmdp.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Autowired
    private ISeckillVoucherService seckillVoucherService;

    @Autowired
    private RedisIdWorker redisIdWorker;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;


    @Override
    public Result seckillVoucher(Long voucherId) {
        // 1. 查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);

        // 2. 判断优惠卷是否启用
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("秒杀尚未开始！");
        }

        // 3. 判断优惠卷是否过期

        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已经结束！");
        }

        // 4. 判断库存是否充足
        if (voucher.getStock() < 1) {
            return Result.fail("库存不足！");
        }
        Long userId = UserHolder.getUser().getId();
        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        boolean isLock = lock.tryLock(1200L);
        if (!isLock) {
            return Result.fail("不允许重复下单");
        }
        try {
            // 获取代理对象
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.getResult(voucherId);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        } finally {
            lock.unlock();
        }

    }

    @Transactional
    public Result getResult(Long voucherId) {
        // 6. 一人一单
        Long useId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", useId).eq("voucher_id", voucherId).count();
        if (count > 0) {
            return Result.fail("用户已经购买过一次！");
        }

        // 5. 扣减库存
        boolean b = seckillVoucherService.update().setSql("stock = stock - 1").eq("voucher_id", voucherId).gt("stock", 0).update();
        if (!b) {
            return Result.fail("扣减库存失败！");
        }

        // 6. 创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);

        // 用户id
        UserDTO user = UserHolder.getUser();
        voucherOrder.setUserId(user.getId());

        // 代金劵id
        voucherOrder.setVoucherId(voucherId);

        save(voucherOrder);
        // 7. 返回结果
        return Result.ok(orderId);
    }
}
